Gradle构建*.so文件无输出问题排查求助

Hey there! I see you're migrating from SCons to Gradle for your C/C++ project, and even though the build says it succeeded, no .so file is showing up. Let's break down what's missing and how to fix it.

What's Going Wrong #

The core issue here is that Gradle's Native plugins don't automatically detect your source files by default. You defined the common NativeLibrarySpec, but you didn't tell Gradle where to find your .cc and .h files. So Gradle thinks there's nothing to compile, skips all the build steps, and reports success without producing any output.

1. Add Source Directory Configuration #

Update your build.gradle to specify the source directory for your common library inside the components block:

model {
    components {
        common(NativeLibrarySpec) {
            sources {
                cpp {
                    srcDir "common/src" // Point to your folder with .cc/.h files
                }
            }
        }
    }
    // Keep your existing binaries configuration here...
}

This tells Gradle to scan common/src for all your C++ source and header files, triggering the compile and link steps properly.

2. Check the Output Path #

Once you rebuild, the .so file on Linux will be in the default output directory:
build/binaries/commonSharedLibrary/
Head there and you should see your shared library.

3. Optional Tweaks for Your Config #

• If your headers are in a separate folder (like common/include), add an exported headers config:

  cpp {
      srcDir "common/src"
      exportedHeaders {
          srcDir "common/include"
      }
  }
  

• The -c flag in your Linux compiler args is redundant—Gradle handles the compile-phase setup automatically. You can simplify that block to:

  if (targetPlatform.operatingSystem.linux) {
      cppCompiler.args '-g', '-fPIC'
      linker.args '-pthread'
  }
  

Gradle C/C++ Docs & Examples #

Official Documentation #

Gradle 4.7 includes comprehensive docs for native builds that you can access locally:

• Run ../gradlew docs to generate local HTML docs, then open the files in build/docs
• Or check the docs folder in your Gradle installation directory—look for the "Building Native Software" section for detailed guides.

Built-in Sample Projects #

You can generate a fully configured C++ library sample project with this command:

../gradlew init --type cpp-library

This creates a standard project structure with proper Gradle config, which you can use as a reference. For more complex examples, you can also look at the subprojects/native-samples directory in Gradle's official GitHub repository (no external links needed—just search for it if you have the repo cloned).

内容的提问来源于stack exchange，提问作者user2569618